Abstract: The invention refers to a plant for treating receptacles adapted to contain a pourable product comprising: at least a treatment unit apt to carry out a treatment process on the receptacles; an isolation chamber housing the treatment unit and containing, in use, a controlled atmosphere controlled in sterile and/or aseptic conditions; and a filtering unit configured to filter a gas to be introduced in the isolation chamber for constituting the controlled atmosphere; wherein the treatment plant further comprises a test device housed inside the isolation chamber, immersed, in use, in the controlled atmosphere and configured to perform one or more test operations on the filtering unit.